摘要 |
PROBLEM TO BE SOLVED: To maintain high adhesion toa copper foil and enlarge discharging capacity for improving a cycle characteristics, with excellent conductive performance or the like of powder itself, by setting a bulk density and oil absorption of graphite powder obtained by pulverizing and classifying a high density isotropic graphite block at specific values, respectively. SOLUTION: The specific resistance of a high density isotropic graphite block is preferably <=20 μΩm and the anisotropic ratio obtained therefrom is preferably 0.9 to 1.1. The powder bulk density of graphite powder is >=0.5 g/cm<3> and the oil absorption thereof is <=65 ml/100 g. Such a carbon material can increase a filling active material amount at the time of sheeting, and greatly increase adhesion to a copper foil as a current collector. A carbon material having a particle size distribution of 5 μm<=10%D (grain size) <=20 μm, 10 μm<=50%D<=35 μm and 30 μm <=90%D<=65 μm is used, can further increase the effects. |